The present invention relates to connectors for interconnecting conduits and in particular, though not exclusively, to connectors for interconnecting conduits, such as pipe for carrying for example oil and/or gas, in subsea locations involving the connection of conduits at a subsea installation.
In one such situation, it is necessary to connect conduits located at the subsea installation to conduits which extend above sea level in order to provide a flow line from the installation. A sea-going vessel tows the open end of a conduit extending to above sea level into the vicinity of the open end of another conduit extending from the subsea installation. The two conduit ends are then roughly aligned and interconnected by a suitable connector in a sealing manner.
One known type of connector for interconnecting the conduit ends consists of an annular seal and clamp which are carried by an installation tool to the generally aligned conduit ends. The installation tool is then required, in successive operations: to engage with each conduit and align the conduit ends; to lower the seal between the conduit ends; to move one or both conduit ends towards the seal; to actuate the clamp to effect clamping of the two conduit ends against the seal; and then to disengage from the conduits for retrieval of the installation tool. Thus, in order to complete the interconnection of the conduit ends, five successive operations have to be carried out and the installation tool is required to perform three main tasks which necessitates the use of highly complex and expensive machinery to achieve the task manoeuvres. Furthermore, because the operations are carried out successively the whole installation procedure takes some time to complete, thereby further adding to the cost.
In another known type of connector, a telescopic sealing unit containing tubular seals slidable by a worm and wheel mechanism, is lowered by an installation tool between the generally aligned conduit ends with the unit also engaging around the conduit ends. Precise alignment of the conduit ends is achieved by friction clamping. The installation tool is then required to actuate the worm and wheel mechanism to slide the seals outwardly into sealing engagement with the conduit ends. The tool is then retrieved. Thus, although this procedure is less complex than the aforementioned procedure, there are still three successive operations to be carried out and the installation tool is still required to perform one main task, namely actuation of the worm and wheel mechanism. Furthermore, large locking forces are experienced by the seals themselves, which creates the possibility of damage.